HP 3000 Manuals HP 3000 Manuals
Choosing Intermediate or Generated Code If you want to run your code in an unlinked environment, you can choose whether you want the cob command to output intermediate or generated (native) code. See the chapter COBOL System Interface (cob) in your COBOL System Reference for details of how you can do this. For maximum performance, process your programs to native code, as native code programs execute more quickly than intermediate code programs. However, there is a qualification to this. A program that is I/O bound (that is, spends most of its time moving data to and from files and devices rather than performing arithmetic on it) derives relatively little benefit in speed from code generation. Only programs that are processor bound (that is, spend most of their time operating on data rather than transferring it) are likely to increase their run-time speed significantly as a result of code generation. Although native code gives better performance than intermediate code, you should be aware that the native code version of a program usually takes up more space than its intermediate code equivalent, as intermediate code is very compact. You must thus ensure that you have enough memory and disk space available to cope with the space overheads of native code. If your program is divided into a main COBOL program and a number of subprograms called from the main program, some of the programs can be processed to intermediate code, others to native code. You can mix the two quite freely.